14. Currently receiving treatment, including medications and herbal preparations, with known strong inducers or inhibitors of cytochrome p450 enzymes CYP3A4/5 medications that have a narrow therapeutic window and are predominately metabolized through CYP3A4/5 or herbal preparations/medications, dietary supplements, which cannot be discontinued at least one week prior to receiving investigational drug. Anti-retrovirals, anti-microbials, and anti-arrhythmics are the most common medications that interact with these enzymes. Section 5: Pharmaceutical Information and Appendix B for more information and a list of drugs that should not be used concurrently with ribociclib. An additional reference can be the CT scholar tool designed for Novartis Oncology